Power unit system



Aug. 28, 1945. E. A. RocKwl-:LL 2,383,618

` POWER UNIT 'SYSTEM Filed June 18, 1940 5 Sheets-Sheet l OCD: FE.-

f BY qb w g mw x m ATTORN Aug- 28, 1945' E. AROCKWELL 2,383,618

POWER UNIT SYSTEM Filed June 18, 1940 5 Sheets-Sheet 2 INVENTOR i? ATTORNE Aug- 28, 1945' E. A. RocKwELL 2,383,618

v POWER UNIT SYSTEM 3 Sheets-Sheet .'5

Filed June 18. 1940 m@ mm..

A INVENTOR QAM 'BY GMM I ATroRNE Patented Aug. 28, A1945 UNITED P Edward A. Rockwell,westgiiartf, Conn.,'fas

signor to The Ncwf-Britain. Machine Co.,-N ew Britain, Conn.,` a corporation of Connecticut Application June 1s, 1940, semi No. 341,104

My invention relates particularly to an improved form of power unit system and which is applicable especially for the delivery of power on automotive vehicles, such, for instance, as automobiles, or for the operation of accessories thereon, such for instance as wheel brakes.

The present application relates to a power unit system which is an improvement over the power unit as set forth in my application upon Powerr system, Ser. No. 239,436, filed November 8, 1933.

fIhe object of my invention is to provide anv improved form of power unit of the character above referred to, so as to more effectively deliver the power for the operation of the said accessories and wherever power is to be applied. One of the objects of my invention is to provide means whereby the brakes or other accessories may` be more effectively operated manually in 11 claims. (01.60-54.15)y

the case of the failure of the power, as for instance the vacuum applied to the said power unit. Another object is to provide a more effective means for insuring the initial application of the manual force for moving the accessory into its initial position, as for instance before the actual application of the braking force to the wheels, and so as to thereby prevent initially the application of pressures from the power of the power unit on the accessory before the manual force has accomplished the said initialmovement. Another object is to provide an advantageous form of container for the unit in which the uid pressure medium is carried and in which the moving parts are submerged. A further object is to provide means whereby the volume of liquid delivered from the power unit to the accessory may be stepped up by increasing the area of a plunger associated with the power unit as well as the area of the master cylinder piston, so as to accommodate the plunger to the various master cylinder piston sizes and pedal ratios for larger vehicles. Another object is to provide for the operation of another power unit from the power of one of the power units. Further objects of lmy invention will appear `from the detailed description of the same hereinafter.

While my invention is capable'of being car- Fig. 4 is an elevation of the unit taken at the right hand end ofFigs. .2 and 3; Y v

Fig.5 is a transverse section of the valve used for controlling the'deliveryof the liquid from the master cylinderto the operating parts of the power unit;

Fig. 6 isan end elev therein; v

tion of the valve vshown Fig-7 is a perspective view showing the master vcylinder as connected to the power unit'and the pedal;

Fig. 8 is a diagrammatic view showing the relative sizes of the master cylinder pistons and, by `way of example, three alternative sizes of plungers vadapted to be used therewith, respectively, 1n the power unit lfor receiving'the liquid from the master cylinder, Awhich are smaller in area than the master cylinder pistons, the area of the plunger chosen being larger according to the increase in volume of' liquid desired to be applied from the power unit to the accessory; and

Fig. `9"is anenlarged vertical section of the master cylinder. v

In the drawings, I have shown a pedal l mounted on a lever .2 which isvpivoted on a shaft 3A carried by a chassis of an automobile, not

Y shown. A link 4 is attached to said lever 2 intermediate its ends so as to give any desiredv pedal ratio movement of the foot pedal I to thefbrakeoperating link 4. The said link is pivotally connected to an operating lever 5 of a master cylinder 6, which may be any desired form of master cylinder but, for example, such as disclosed in the patent to Loughead, No. 1,707,063, granted March 26, 1929. The lever 5 is carried ona shaft 1 vpassing into the master cylinder 6 which has an armA .8 for operatingfavmaster cylinder piston 9 lcarried in a cylinder fill within a storage chamber having a Vent"|2V and -a filler opening I3. When the pedal ,I vis moved downwardly'the piston 9 is adapted toj discharge liquidfrom'f'thel ing l5 vlocated in al head 1,16 of the poWerunit.

ried out in many different ways,` by way of illusj tration I have shown only paratus whichone form of the apin the accompanying drawings, in'.`

Fig. 1 is an end elevation of a power unit made in accordance with my invention; Fig. 2 is a longitudinal section-of the same taken on line 2 2 of Fig. v1;v Fig. 3 is a view of the apparatus tion taken on line 3-3-of Fig. l;

i therein. partly'vinjsec-` Q5 Y 1 give-,access tctheinterior 'o'fnthe power unit.

The Said head is also'iyconnected.toafdischarge' pipe i1 leadingto-thejusual wheelcylindersl 1b operating shoes f I lajon the brakesof the wheels of the automobilechassisand illustratedjinmy c prior application 'upon-Power, system above 're- Also, as.l sho tion, for example,`t e-sai y A inA said `prior applicad .headfl is connected by-a pipe I8 leading-' otheengine manifold or 'any'other sourcefof acuumfthe same"being*`re ,Y rceived Vin a fitting,

havingla check valve 2U screw. plugsfzlfandfz jlated in said head 1s The said head II acts as a closure for a sheet metal container 23 forming the outside of the power unit and is attached thereto by the container being forced at intervals around its periphery in recesses 24 in said head carrying any desired sealing cement. It will be noted that the container 23 is in the form .of a cylindrical shell having two adjacent U-shaped flanges 25 and 26 which are held together by a longitudinal channel bar 21 adapted to be slid over the ilanges longitudinally and seal the same by clamping a rubber strip 28 between the flanges.

The liquid from the master cylinder 6 is con.- veyed through a passageway 29 in the head I6 and thence through a iittng 39 and pipe 3| to a right angle tting 32 carried on the end of f a cylindrical extension 33 forming a part of the head I5. The sai/d fltting 32 delivers the liquid into a circular recess 34 and thence into a bushing 35 also having a circular recess 36 so as to communicate with a passageway 31, which conveys the liquid by a pipe 38 to a right angle iitting 39 which is connected by a pipe 40 passing through` a sleeve 4| screw-threaded in a'casting 42 at the other end of the container 23, which is attached to said container by means of indentations therein forced from the container in recesses 43 having sealing means as in the case of the recesses 24. This endlof the said pipe is connected to an angular iitting 44 which is screw-threaded into an extension 45 on a sleeve 46 provided with a circular passageway 41 communicating with radial ports 48 leading to a central passageway 49 in a bleeder valve housing 50.

The bleeder valve housing 50 has screwthreaded therein a bleeder valve 5| having a conical end 52 cooperating with a valve seat 53' of the master cylinder pistons used therewith,

it being understood that the pedal lever ratio for each set of diameters will be adjusted therewith to always obtain approximately the same ratio of force from the piston to the force ob- -tained from its plunger in each of the three pairs of pistons and plungers. The plunger 68 has a rubber seal 69 supported in an annular recess 10 thereon at one end of the plunger and the other end thereof having a seal 1| supported `in a recess 12 on a cylindrical extension 13 at its other end, to which there is fastened an outlet valve 14 provided with an annular ange y15 which is adapted to seat, in the closed position of the valve, against a diaphragm 16 of rubber or any other similar material, which is supported on one face of the casting 42 and clamped against the same by means of an annular spacing member 11 and screws 18.

Said spacing member 11 supports on its periphery a .cylinder 19 which is secured thereto by indentations 80 and a sealing compound 8|.

The cylinder 19 is submerged in the vacuum located on the outside of the cylinder 19 and within the container 23 and the said vacuum is communicated by a passage 82 from the space in the passageway r49. When the valve 5| is Y unscrewed air can passby a transverse port 54 into a longitudinal passageway 55 to a point beneath a screw-plug 66 which, when removed, enables the air to escape-when desired.

The liquid thus received in the extension 45 enters `a. passageway 51 in which there is contained means to prevent the feeding of the liquid to the unit too rapidly initially and so as to thereby prevent the powermechanism of the power unit being actuated until after the manual force alone has moved the brake shoes, as for instance up to the point where they are in position to apply the brake force.l This is comprised of a valve member 58 triangular in cross-section, which is forced on a valve seat 59 by a spring 6U but which is adapted to be unseated therefrom by the reverse ilow of the pressure liquid. In the interior of the valve member 58 there is a passageway 8| containing a. spring 62 located around a valve stem G3 and which is seated against an enlargement 64 at one end of said valve .stem and at the other end against a shoulder 55 in the passageway 6|. Said other end of the .valve stem 63 carries a conical valve 66 which is normally seated against its seat on the end of the valve member 58 by means of said spring 62. Thus the valve 56 is unseated initially only to a suillcient extent to allow a restricted amount of liquid to pass by the same and allow the brake shoes to be moved initially merely by the manual force of the `liquid and so as to prevent, in the initial `movement, of the brake shoes, the application thereto of the power unit.

The bleeder valve housing 59 is screw-threaded into a cylinder 51 which in turn is screwbetween the container 23 and the cylinder 19 to the valve 14. Passing through the said spacing member 1l there is also a passageway 83 which communicates with a passageway 84 in a pipe 85, provided for operating another power unit therefrom on the same vehicle or a trailer in the usual way, which is screw-threaded into the casting 42.- This pipe 85 is closed normally by a plug 86. The pipe 95 extendsthrough a cap 81 supported by the bleeder valve housing 50 and which has around its inner edge an open space 88 for the admission of air through an annular air inlet opening 89 in a cover 90, also supported on the bleeder v alve housing 5D and at its periphery on the casting 42. A gasket 9| makes a -dust-tight joint at this point.

The cover 90 has within the same a body of 55" horse-hair 92 to filter out any dust from the air admitted to the unit. The said air, after passing through the body of horse-hair 92, ls then conveyed through la screen 93 and a passageway 94 in the casting 42 to a similar passageway 95 in the spacing mernber 11 so as to be supplied thereby to an air inlet valve 96 located within the spacing member 11 and which has a flange 91 also seating on the diaphragm 16.

I'he said valve 96 is supported by means of a diaphragm 98 of rubber or similar material, clamped at its periphery to one face of the spacing member 11 by a clamping plate 99 with the aid of the said screws 18. The inlet valve is fastened to the central portion of the diaphragm 98 by a ring |08 and a sleeve ||l| having a flange |02 for this purpose. The side of the said sleeve IM has one or more ports |03 communicating' member |31.

phragm 18 by means of a. ring |05 and a ange located at this end of the sleeve |0I. In this way it will be noted that the two diaphragms 10 and 50 are secured together with the inlet valve 36 at their central portions.

In the interior of the sleeve |0| -a helical spring |01 is seated at one end against'a shoulder |03 within the said sleeve and at the other end against the face of the clamping plate 03 and thus normally tends to move the inlet valve 30 to the left in Fig. 2, so as to seat the inlet valve 30 on the diaphragm 16 opposite to a portion of the casting 42. Within the said spring |01 there is a smaller spring |03 which' seats at one end around a reduced extension on the cylindrical clamping plate 93 and at the other end against' the plunger 13, thus tending to normally unseat the outlet valve 14. Y

It will be noted that the clamping -plate 33 has therein one or more ports 0 so as to give access for the pressure medium to the face of a piston which is adapted to move within the cylinder 10. The said piston I is provided with a right angle recess l2 at its periphery to receive a leather gasket l I3 having a right angle crosssection and which is maintained in position by a spring ring 4 cooperating with a ring ||5 of felt or similar material. A retainer disk ||6 is -provided for keeping the gasket ||3, the felt ring and the spring ring |4 in position. The said piston and the retainer plate ||5 are clamped together on a piston plunger rod ||1 by means of nuts H8 and` H3, which .also clamp in position a spring retaining cup |20 for receiving one end of a, coil spring 2|, the other end oi' which is supported :by a plate |22 having three or more spaced ears |23 bent into openings |24 on the cylinder 19 and a supporting flange |24a for holding the said spring in place. n

The rod ||1, at its right hand end in Fig. 2, acts as a plunger and for this purpose passes through a sleeve |25 having a packing |28 held in place by a split ring |21 and a rubber sealing ring |20. The said sleeve |25 is screw-threaded into the extension 33 of the head I6 so as to permit the plunger ||1 to pass through a central passageway |29 in the bushing 35. When the piston is moved to the right, in Fig. 2, the said plunger ||1 passes through an annular seal |30 held in place by a perforated anged ring |3|, the flanged end of which seats against a shoulder |32. The continued movement of the plunger ||1 in this direction causes the plunger to enter a cylindrical chamber |33 in the said extension 33 so as to place the liquid therein under a high pressure of from 1000 to 1500 pounds per square inch, and thus supply the same by the pipe |1 to the wheel cylinders for operating the brakes of the automobile.

Should the vacuum from the manifold be ineifective for any reason it will be understood that the .'brakes of the automobile can be operated manually, nevertheless, and this is facilitated in accordance 'with my present invention lby providing a cross-passageway |34 leading from the inlet port 23 to the interior of the cylindrical chamber |33, and which is normally closed by a ball check valve |35 normally pressed against its seat |36 in a screw-threaded valve The ball valve |35 is thus forced against said seat by a spring |38 carried in a anged spring housing |30 supported within the passageway |30 and secured therein by the screwthreaded valve member |31.

In the operation of the power unit made iny accordance with my invention, when the brakes are to be applied the pedal having any desired pedal ratio, is pushed downwardly thus operating the lever 5 on the master cylinder 0 and moving the piston 3 to the right. The liquid is thus forced by the piston/3 through the pipe I4 and thence into the power unit and by means of passageways 20, 3|, 34 and 36, thence into the cylindrical chamber |33 so as to lbe supplied to the" brake cylinders for moving the shoes manually into snugly tting position so that upon further increase of the hydraulic power applied thereto the braking force will be further applied to the wheel cylinders by the application of power.

A It will be understood that if for any reason the vacuum is ineective the .braking force can be quickly and effectively applied manually by in creasing the pressure applied to the pedal. This is accomplished with the avoidance of lag. and even if the plunger ||1 should, for any reason, have entered the seal |30, by the hydraulic liquid being forced past the check valve |35 into the cylinder |33 and thence to the brakes.

In the normal operation of the apparatus,

`as the pedal pressure is increased the liquid is conveyed from the passageway 3|;` around the end or side of the plunger ||1 to the passageways 31, 38 and 40 into the valve passageway 6| where the spring-retracted valve 66 permits, initially, only a restricted flow of the liquid so as thus to exert the manual force for bringing the power unit into action only after the brake shoes have been ymoved into position manually. Due to the initial restricted iiow of the liquid the plunger 68 is prevented from being operated too suddenly by the sudden application of the foot pressure, thus avoiding the possibility, which would otherwise be present, of the piston being moved before the manual force on the hydraulic liquid has moved the brake shoes into the position and before increasing the braking force.

This plunger 68, as referred to above, may be of various sizes, as shown in Fig. 8, se that a plunger of increasing size may be chosen according to the increase in size of the master cylinder piston used to obtain increased volume of liquid in operating heavier vehicles, such as heavyduty trucks, etc. However, the master cylinder piston and the plunger 08 used are of such relative sizes as to obtain for all vehicles the same ratio of force on the plunger 68 to the force exerted on the piston I, approximately, so as to maintain the same foot-pressure range. It will be understood, however, that the area of each of these plungers is smaller than the area of the master cylinder piston as thereby a decreased force is obtained as compared with the force delivered by the master cylinder piston. Of course, in substituting a different size plunger 08 a cylinder 61 will be used to t the same.

The plunger 68 is thus moved by the increase of the manual pressure until the outlet valve 14 becomes seated on the diaphragm 16 and thereafter 4the inlet valve 96 is moved oil its seat on the said diaphragm by the force exerted on the cylindrical member 13. Ihis shuts oil the vacuum from access through the sleeve 0| to the left face of the piston in Fig. 2. and admits the air from the atmosphere through the space 08, inlet 83, passageways 94 and 95 and beneath the inlet valve 96 through the ports |03, sleeve |0| to the said face of the piston Consequently, owing to the vacuumwhich is present on the right face of the said piston the pressure of the atmospheric air forces the -square inch. However, the plunger II'I beginsl to moveto the right when the pressure in the pressure, a source of pressure uid diiering from the atmospheric pressure for actuating said movable means, a control means controlling the movement ofthe movable means, and a springrestrained pressure-responsive forwardly feeding valve mounted in a spring-pressed reverse-flow cylinder |33 reaches 150 pounds per square inch.

This results in the braking force being applied to the brake shoes.

The braking effect, when the brakes are set, is obtained by modulated pressures, producing reactions on the foot coordinated with the pressures applied on the brake cylinders, and this is accomplished merely by the movement of comparatively small amounts of the hydraulic liquid by the foot and at the very high pressures obtained from 'the power unit to the brake cylinders.

While I have described my invention above in detail I wish it to be understood that many changes may be made therein without departing from the spirit of the same.

I claim:

1. A power'unit comprising means for delivering a manually .supplied uid to said unit for controlling the said unit, movable means in said unit adapted to deliver from the unit a uid under a pressure greater than` the manual pressure, a source of pressure fluid diiering from the `atmospheric pressure for actuating said movable means, a control means controlling the movement of the movable means, and a valve, having a pressure-responsive mounting, adapted to control the delivery of the manually supplied fluid so as to actuate the control means at a predetermined pressure.

2. A power unit comprising means for delivering a manually supplied hydraulic liquid to said unit for controlling the said unit, movable means in said unit adapted to deliver from the unit a uid under a pressure greater than the manual pressure, a source of pressure fluid differing from the atmospheric pressure for actuating said movable means, a control'means controlling the movement of the movable means, and a spring-restrained forwardly feeding and reverse flow relief valve adapted to permit the forward passage through the valve only of an amount determined by said spring of the manually supplied hydraulic i liquid so as to actuate the control means at. a prel determined pressure.

, 3. A power unit comprising means for deliver- 'ing a manually supplied liquid to said unit for controlling the said unit, movable means in said unit adapted to deliver from the unit a fluid under a pressure greater than :the manual pressure, a source of pressure fluid differing from the atmospheric pressure for actuating said movable means, a control means controlling the movement of the movable means, and a pressure-responsive forwardly feeding valve mounted in a reverse-flow relief valve, adapted to control the delivery of the manually supplied liquid so as to actuate the control means at a predetermined pressure but permit the reverse flow of the liquid.

4. A power unit lcomprising means for delivering a manually supplied hydraulic liquid to said unit for controlling the said unit, movable means in said unit adapted to deliver from the unit a fluid under a pressuregreater than the manual valve adapted to retard the delivery of the liquid so as to actuate the control means at a predetermined pressure.

5. A power unit comprising means for delivering a manually supplied hydraulic liquid thereto for controlling the said unit, means therein for delivering therefrom a fluid under a pressure greater than the manual pressure supplied, a source of pressure uid different from the atmospheric pressure for actuating said means, and a cylindrical enclosure for said unit containing said pressure uid differing from the atmospheric pressure, having longitudinal adjacent flanges and a channel -bar clamping the flanges together.

6. A power unit comprising means for delivering a manually supplied hydraulic liquid thereto for controlling the said unit, means therein for delivering therefrom a iiuid under a pressure greater than the manual pressure supplied, a source of pressure iluid diifering from the atmospheric pressure for actuating said means, and a cylindrical enclosure for said unit containing said pressure fluid differing from the atmospheric pressure, having longitudinal adjacent iianges, an intervening elastic strip and a channel bar clamping the flanges together.

'7. A power unit having an inlet for a manually controlled hydraulic liquid; a hydraulic connection therefrom leading to a part to be operated, a source of pressure fluid diiering from the atmospheric pressure, a movable wall, valve means in the unit comprising inlet and outlet valves for controlling said movable wall from said pressure fluid, an enclosure for said valves, a plunger in the manually controlled hydraulic liquid, said plunger being removably associated with said valve means a spring seating against the plunger for operating the latter and a cylinder, in which said plunger slides, removably mounted on said enclosure, arranged to enable plungers and cylinders of different diameter to be associated with said valve means. V

8. A power unit having an inlet for a manually controlled hydraulic liquid, a hydraulic connection therefrom leading to a part to be operated, a source of pressure fluid diifering from the atmosp-heric pressure, a movable wall, valve means in the unit comprising inlet and outletv valves for controlling said movable wall from said pressure fluid, an enclosure for said valves, a plunger in the manually controlled hydraulic liquid, said plunger being removably inserted in said valve means a spring seating against the plunger for operating the latter and a cylinder, in which said plunger slides, removably mounted on said enclosure, arranged to enable plungers and cylinders of different diameter to be associated with said valve means.

I 9. A power unit having an inlet fora manually controlled hydraulic liquid, a hydraulic connection therefrom leading to a part to be operated, a source of pressure iiuid differing from the I atmospheric pressure, a movable wall, valve means 1n the unit comprising inlet and outlet valves for controlling said movable wall from said pressure fluid, an enclosure for said valves, a plunger in the manually controlled hydraulic liquid, said plunger being removably inserted in said valve means for operating the latter, a cylinder. in

which said plunger slides, removably mountedv on said enclosure, arranged to enable plungers and cylinders o! dierent diameter to be associated with said valve means a peripheral seal located around the plunger anda retracting spring seated against the plunger. ,Y

10. A power unit having an inlet for a manually controlled hydraulic liquid, a hydraulic con; nection therefrom leading'to a part to be operated, a source of pressure uid differing from the.

atmospheric pressure, a movable wall, valve means in the unit comprising inlet and outlet ond hydraulic connection power unit comprising a fluid pressure actuated member.' valve means for controlling pressure fluid for actuationof said member', hydraulically actuated means for actuating said valve means, an hydraulic cylinder, a plunger operable therein andactuable by said uid pressure actuated member, a low pressure hydraulic connection to said hydraulically actuated means and to said hydraulic cylinder, means for cutting oli-communication between said low pressure hydraulic connection and said hydraulic cylinder when said plunger is advanced in said cylinder, and a sec- !between said low pressure hydraulic connection and said hydraulic cylinder, and a check valve in said second hydraulic connection and opening toward said cylinder, whereby low. pressure hydraulic fluid may be forced through said second connection past said check valve when said rst mentioned hydraulic connection to said hydraulic cylinder is cut oil', for the purpose set forth.

EDWARD A. ROCKWELL. 

